for (auto input_output :
         llvm::zip(pack_op.getOperands(), input_unpack_op.getResults())) {
      Value pack_input = std::get<0>(input_output);
      Value unpack_output = std::get<1>(input_output);
      // Make sure the ordering is the same for the pack op & unpack op.
      if (pack_input != unpack_output) return failure();
    }

    // Replace the pack's output to the unpack's input.